An integrated circuit (IC) in which an autofocus drive control unit is mounted and a lens driver IC are normally connected by serial communication such as inter-integrated circuit (I2C) communication, and the IC having the drive control unit mounted therein is designed to control driving of the lens driver IC.
The communication format specifications of lens driver ICs vary with makers and products. The drive control unit side that controls driving of a lens driver IC should have a transmission format portion mounted therein in accordance with the communication format specification of the lens driver IC to be connected thereto.
Further, as for an actuator that moves an autofocus (AF) lens, there is a type that moves the lens position with a bidirectional current value. As for lens driver ICs that drive the actuator, there are a type that associates drive current values only with “unsigned” or positive values as input digital analog converter (DAC) code specifications, and a type that associates drive current values with “signed” or positive and negative values. The AF control system side needs to prepare the DAC code values to be output, in accordance with the input DAC code specification of the lens driver IC to be connected thereto.
In view of this, a technology for automatically determining the types of communication formats of different lens driver ICs or the like and then switching transmission formats has been suggested (see Patent Document 1).